Fabrication of Nanopillars comprised of InGaN/GaN Multiple Quantum Wells by Focused Ion Beam Milling

摘要

Most studies conducted on III-nitride top-down fabrication were only devoted to some etching routes like inductively coupled plasma (ICP) etching and reactive ion etching (RIE) [1,2]. In this work, fabrication of nanopillars containing InGaN/GaN multiple quantum wells (MQWs) are demonstrated by focused ion beam (FIB) using a modified beam-shape tuning [3]. The anomalous phenomenon of this approach leaving behind high-aspect-ratio InGaN/GaN MQWs nanopillars is discussed. High-resolution cross-sectional transmission electron microscopy (XTEM) revealed the retained single-crystalline nature of these pillars, while cathodoluminescence (CL) spectra revealed the intensity enhancement of InGaN/GaN MQWs emission upon wet-etching.